Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Excretory system, What are the excretory organ in protozoa,coelenterates, i...

What are the excretory organ in protozoa,coelenterates, insects,spider,and arthropods

What are the applications of pcr, Polymerase chain reaction already has ext...

Polymerase chain reaction already has extremely widespread applications and new uses are being devised on a regular basis. Some and definitely not all of the applications are given

Do squids and octopus have exoskeleton, Q. Do squids and octopus have exosk...

Q. Do squids and octopus have exoskeleton? Squids and Octopus generally do not produce external shell (some squid species can have an internal shell). One cephalopod group the

Importance of primary prevention of diabetes mellitus, Q. Importance of Pri...

Q. Importance of Primary prevention of diabetes mellitus ? Primary prevention has been found to be cost effective in the long run as it reduces unwarranted human suffering. Pre

Explain scombroid poisoning, Q. Explain scombroid poisoning? Ingestion ...

Q. Explain scombroid poisoning? Ingestion of improperly handled and stored seafood (yellow-fin tuna, skipjack, bonit and mackerel) causes scombroid poisoning. Maitoxin has been

Define briefly about vitamin B1, Vitamin B 1 (Thiamine hydrochloride) ...

Vitamin B 1 (Thiamine hydrochloride) a) Thiamine hydrochloride is a white, crystalline powder, slightly hygroscopic, of an odour resembling yeast and of bitter to taste. b)

Which are the organs of the excretory system, Which are the organs of the e...

Which are the organs of the excretory system? The excretory system is produced of kidneys (two), ureters (two), bladder and urethra. The Excretory System - Image Diversity:

Controlled percussive instruments, Percussive instruments -this method...

Percussive instruments -this method used a selected and controlled percussive removal force -Instruments delivers an impact either directly to a restorative or indirectly t

Determine the sucrose content in a sample of honey, Q. Determine the sucros...

Q. Determine the sucrose content in a sample of honey? This activity will help you to: • estimate the non-reducing sugars and total sugars in a sample of honey, • check t

Define gluconeogenesis, What is gluconeogenesis? Highlight its significance...

What is gluconeogenesis? Highlight its significance giving any two examples Gluconeogenesis (i.e synthesis of new glucose) is the synthesis of carbohydrate from non-carbohydrat

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd